INST 327 Study Guide - Fall 2018, Comprehensive Midterm Notes - Mysql, Sql, Database
12 Oct 2018
School
Department
Course
Professor
INST 327
MIDTERM EXAM
STUDY GUIDE
Fall 2018
INST427 Lecture 1: Introduction
What is a Database?
A database is a separate application that stores a collection of data. Each database has
one or more distinct APIs for creating, accessing, managing, searching and replicating
the data it holds.
Other kinds of data stores can also be used, such as files on the file system or large
hash tables in memory but data fetching and writing would not be so fast and easy with
those type of systems.
Nowadays, we use relational database management systems (RDBMS) to store and
manage huge volume of data. This is called relational database because all the data is
stored into different tables and relations are established using primary keys or other
keys known as Foreign Keys.
A Relational DataBase Management System (RDBMS) is a software that −
● Enables you to implement a database with tables, columns and indexes.
● Guarantees the Referential Integrity between rows of various tables.
● Updates the indexes automatically.
● Interprets an SQL query and combines information from various tables.
RDBMS Terminology
Before we proceed to explain the MySQL database system, let us revise a few
definitions related to the database.
find more resources at oneclass.com
find more resources at oneclass.com
●Database − A database is a collection of tables, with related data.
●Table − A table is a matrix with data. A table in a database looks like a simple
spreadsheet.
●Column − One column (data element) contains data of one and the same kind,
for example the column postcode.
●Row − A row (= tuple, entry or record) is a group of related data, for example the
data of one subscription.
●Redundancy − Storing data twice, redundantly to make the system faster.
●Primary Key − A primary key is unique. A key value can not occur twice in one
table. With a key, you can only find one row.
●Foreign Key − A foreign key is the linking pin between two tables.
●Compound Key − A compound key (composite key) is a key that consists of
multiple columns, because one column is not sufficiently unique.
●Index − An index in a database resembles an index at the back of a book.
●Referential Integrity − Referential Integrity makes sure that a foreign key value
always points to an existing row.
MySQL Database
MySQL is a fast, easy-to-use RDBMS being used for many small and big businesses.
MySQL is developed, marketed and supported by MySQL AB, which is a Swedish
company. MySQL is becoming so popular because of many good reasons −
● MySQL is released under an open-source license. So you have nothing to pay to
use it.
● MySQL is a very powerful program in its own right. It handles a large subset of
the functionality of the most expensive and powerful database packages.
● MySQL uses a standard form of the well-known SQL data language.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
A database is a separate application that stores a collection of data. Each database has one or more distinct apis for creating, accessing, managing, searching and replicating the data it holds. Other kinds of data stores can also be used, such as files on the file system or large hash tables in memory but data fetching and writing would not be so fast and easy with those type of systems. Nowadays, we use relational database management systems (rdbms) to store and manage huge volume of data. This is called relational database because all the data is stored into different tables and relations are established using primary keys or other keys known as foreign keys . A relational database management system (rdbms) is a software that . Enables you to implement a database with tables, columns and indexes. Guarantees the referential integrity between rows of various tables. Interprets an sql query and combines information from various tables.
